Granular Materials Studied By MRI
Final rept. 1 Jun 95-31 Dec 98
LOVELACE INSTITUTES ALBUQUERQUE NM
Pagination or Media Count:
This letter supplements the final report of August 1998 on Additional Objective To Obtain the Structures of Asphalt Composite, which was part of the project Granular Materials Studied by MRI. We had our hydrogen-free bird cage coil rebuilt to get the background signal below that of the hydrogen in asphalt tar. We now present two images, one of tar in asphalt, one of SF6 gas in the pores of the asphalt. The asphalt came from Western Mobile Corporation, Albuquerque. We packed it, while hot, into a plastic syringe, to form a 2.5 cm diameter, 4 cm long cylindrical pellet. To image the pore spaces, we flushed the sample several times with SF6 gas, and then compressed the gas to approximately two atmospheres for imaging. To image the tar, we removed the sample from the syringe and supported it with a Teflon sheet to eliminate the syringe, which is easier to image than the tar in asphalt. Consistent with our experience with other sand and gravel products, asphalt contains paramagnetic or ferromagnetic materials that cause severe inhomogeneities in the magnetic field.
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